1. Field of the Invention
The present invention relates to an organic EL display device.
2. Description of the Related Art
In recent years, an image display device using a self-luminous body called an organic light-emitting diode (OLED) (hereinafter referred to as an “organic EL (Electro-Luminescent) display device”) has been put to practical use. Since the self-luminous body is used, the organic EL display device is superior in terms of visibility and response speed compared to a related-art liquid crystal display device, and in addition, a further reduction in thickness is possible because an auxiliary lighting device such as a backlight is not necessary.
For color display in such an organic EL display device, there are primarily two kinds of methods: one is to provide light-emitting elements that respectively emit lights of three colors of R (red), G (green), and B (blue) for each pixel; and the other is to emit white light in light-emitting elements and allow lights in respective wavelength ranges of three colors of R, G, and B to transmit through color filters of pixels.
JP 2003-272860 A discloses an organic EL element using a charge generation layer. JP 2010-146893 A discloses an organic EL element in which a film having a high haze value is provided to improve light extraction efficiency. JP 2010-192472 A discloses an organic EL element in which the refractive index of an anode and the refractive index of a substrate are set so as to satisfy a predetermined condition to enhance light extraction efficiency.